X-Band Microstrip AlGaN/GaN HEMT Power MMICs

X-Band AlGaN/GaN HEMT power MMIC on Sl-SiC designed in microstrip technology is presented in this paper. Recessed-gate and field-plate are used in the device process to improve the AlGaN/GaN HEMTs performances. S-parameter measurements show a strong dependence of the frequency performances of the AlGaN/GaN HEMTs on the operating voltage. Higher operating voltage is key to get higher power gain for the AlGaN/GaN HEMTs. The developed 2-stage power MMIC delivers a pulsed output power in excess of 10 W at a drain bias of 30 V with a power gain of more than 12 dB over the band of 9-11 GHz. Peak output power inside the band reaches 14.7W with a power gain of 13.7dB and a power-added- efficiency (PAE) of 23%. The MMIC chip size is only 2.0 mm times 1.1 mm. This work shows superiority over reported results of X-band AlGaN/GaN HEMT power MMICs up to date in output power per millimeter gate width and output power per unit chip size.